Method for producing electric-mechanical acoustic converter

ABSTRACT

The present invention relates to an electric-mechanical-acoustic converter used mainly in a mobile telephone and the like, and its objective is to provide a high-quality product in which damage and degradation of performance caused by shock due to a drop are prevented.  
     In order to achieve this objective, the present invention includes at least one suspension ( 14 ) supporting a movable portion ( 19 ) formed of the magnetic circuit portion ( 17 ) and a weight portion ( 13 ), and a frame ( 9 ) supporting a diaphragm ( 8 ) and the suspension ( 14 ), a space in an elastic deformation range of the suspension ( 14 ) being provided between the outer periphery of the movable portion ( 19 ) and the frame ( 9 ). Even in the case where a portable terminal apparatus is dropped, and the electric-mechanical-acoustic converter built therein is subjected to shock, the outer periphery of the movable portion ( 19 ) is received by the frame ( 9 ), whereby the suspension ( 14 ) can be prevented from being permanently deformed.

TECHNICAL FIELD

[0001] The present invention relates to an electric-mechanical-acousticconverter for vibrating or generating a sound with an electric signal,and a method for producing the same.

BACKGROUND ART

[0002] Conventionally, in a portable terminal apparatus such as a mobiletelephone, as means for notifying an incoming call, a small soundgenerator which generates a bell sound and a micromotor in which aweight is eccentrically attached to a rotation axis so as to causevibration have been used as separate functional components. Furthermore,in order to listen to a conversation of a person on the other end of theline, it is required to attach a speaker for receiving a conversation.

[0003]FIG. 6 is a cross-sectional side view of anelectric-mechanical-acoustic converter used in the above-mentionedportable terminal apparatus. The background art will be described withreference to this figure. In order to achieve further miniaturizationand lighter weight of a portable terminal apparatus, theelectric-mechanical-acoustic converter in FIG. 6 achieves both soundgeneration and vibration so as to reduce the number of components.

[0004] Referring to FIG. 6, an outer peripheral portion a circulardiaphragm 1 is attached to a case 2. The case 2 has a bottom plate 5,and a yoke 3 is fixed to the bottom plate 5. A suspension 6 is supportedby the case 2, and a magnet 4 is supported by the suspension 6. A voicecoil 7 consisting of a bobbin and a coil both ends of which areconnected to a terminal (not shown) to which an electric signal is inputfrom outside is inserted in a magnetic gap formed by an inner peripheralsurface of the yoke 3 and an outer peripheral surface of the magnet 4,and one end of the voice coil 7 is fixed to the diaphragm 1.

[0005] The yoke 3 and the magnet 4 form a magnetic circuit portion andthe suspension 6 and the magnet 4 form a mechanical vibration system.

[0006] Next, the operation will be described. In the above-mentionedelectric-mechanical-acoustic converter, an action-reaction force worksbetween the voice coil 7 and the magnetic circuit portion, when anelectric signal is applied to the voice coil 7 from outside. Supposethat a force applied to the voice coil 7 is an action force, thediaphragm 1 to which the voice coil 7 is attached vibrates due to theaction force.

[0007] Furthermore, due to the reaction force applied to the magneticcircuit portion, the magnet 4 supported by the suspension 6 vibrates,and vibration is transmitted to the case 2 through the suspension 6,whereby the case 2 vibrates. The resonance frequency of the magneticcircuit portion is in a low band. Therefore, an electric signal at afrequency in this low band is applied to the voice coil, wherebyoutstanding vibration can be obtained.

[0008] However, there is a possibility that the portable terminalapparatus such as a mobile telephone is dropped while being carried dueto its portability, and there is a possibility that anelectric-mechanical-acoustic converter built in the portable terminalapparatus will be deformed and damaged by the shock caused by such adrop.

[0009] The present invention solves the above-mentioned problem, and itsobjective is to provide an electric-mechanical-acoustic converter whichhas outstanding resistance to shock and in which the resonance frequencyof vibration is stabilized.

DISCLOSURE OF THE INVENTION

[0010] In order to solve the above-mentioned problem, theelectric-mechanical-acoustic converter of the present invention includesa diaphragm, a magnetic circuit disposed so as to oppose the diaphragm,a voice coil one end of which is attached to the diaphragm and which isinserted into a magnetic gap of the magnetic circuit with apredetermined space, a weight integrated with the magnetic circuit orattached thereto as a separate component, at least one suspensionsupporting a movable portion composed of the magnetic circuit and theweight, and a frame supporting the diaphragm and the suspension, a spacein an elastic deformation range of the suspension being provided betweenthe outer periphery of the movable portion and the frame. Even in thecase where the portable terminal apparatus is dropped, and theelectric-mechanical-acoustic converter built therein is subjected toshock, the outer periphery of the movable portion is received by theframe, whereby the suspension can be prevented from being permanentlydeformed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1(A) is a cross-sectional side view of an example of anelectric-mechanical-acoustic converter of the present invention. FIG.1(B) is an exploded perspective view of FIG. 1(A). FIG. 2 is aperspective view of an assembly of a movable portion and suspensionswhich are main portions of another example of anelectric-mechanical-acoustic converter of the present invention. FIG. 3is a perspective view of an assembly of a movable portion andsuspensions which are main portions of still another example of anelectric-mechanical-acoustic converter of the present invention. FIG. 4is an exploded perspective view of still another example in FIG. 3. FIG.5 is a partial cross-sectional side view showing a state where stillanother example in FIG. 3 is provided in a mobile telephone. FIG. 6 is aside cross-sectional view of a conventional electric-mechanical-acousticconverter.

BEST MODE FOR CARRYING OUT THE INVENTION EXAMPLE 1

[0012] Hereinafter, an example of an electric-mechanical-acousticconverter of the present invention will be described with reference toFIGS. 1(A) and 1(B).

[0013] As shown in these figures, reference numeral 8 denotes adiaphragm made of a film with a thickness of about 50 μm, for example,and the diaphragm 8 is attached at an outer periphery to a frame 9 madeof resin or the like. Reference numeral 10 denotes a yoke, which has acylindrical shape having a bottom, made of a ferromagnetic substancesuch as soft iron. Reference numeral 11 denotes a magnet, which isformed of a permanent magnet of neodymium and has a cylindrical shape.The magnet 11 is fixed to a central portion of the yoke 10. Referencenumeral 9 a denotes a cover.

[0014] Reference numeral 12 denotes a plate made of a ferromagneticsubstance, which is fixed to the magnet 11 on the diaphragm 8 side.Reference numeral 13 denotes a weight portion, which is integrated withthe yoke 10. Reference numeral 14 denotes suspensions which are composedof two arc-shaped arms extending in a circumferential direction. A pairof the suspensions 14 are provided on upper and lower surfaces of theyoke 10. One end of each suspension 14 is fixed at the weight portion13, and the other end thereof is molded with resin to be fixed at aconcave portion 15 of the frame 9. A connected portion between eachsuspension 14 and the frame 9 is molded with resin to form a moldportion 16, whereby a fulcrum of each suspension 14 is determined withgood precision, and performance thereof is stabilized. When the moldportion 16 is inserted into the concave portion 15 of the frame 9,adhesion strength of the mold portion 16 is also obtained.

[0015] The yoke 10, the magnet 11, and the plate 12 form a magneticcircuit portion 17, and an inner surface of the yoke 10 and an outersurface of the plate 12 form a magnetic gap.

[0016] A cylindrical voice coil 18 is inserted into the magnetic gap,and one end of the voice coil 18 is attached to the diaphragm 8. Themagnetic circuit portion 17 forms a movable portion 19 which is operatedrelative to the frame 9, and the suspensions 14 and the movable portion19 form a mechanical vibration system.

[0017] A space 20 in an elastic deformation range of the suspensions 14is provided between an outer periphery of the movable portion 19 and aninner diameter of the frame 9. Furthermore, this space 20 is set to besmaller than the space between the magnetic gap and the voice coil 18.Because of this, even when the movable portion 19 is moved by shock, theinner diameter of the frame 9 receives the outer periphery of themovable portion 19. Therefore, the suspensions 14 return the movableportion 19 to the original position without being permanently deformed.Furthermore, since the outer periphery of the movable portion 19 isreceived by the frame 9 before the magnetic gap comes into contact withthe voice coil 18, the voice coil 18 can be prevented from beingdamaged.

[0018] The operation of the electric-mechanical-acoustic converter thusconstructed will be described. When the voice coil 18 receives anelectric signal from outside, an action-reaction force works between thevoice coil 18 and the magnetic circuit portion 17. Suppose that a forceapplied to the magnetic circuit portion 17 is a reaction force, thereaction force is supported by the suspensions 14 and is applied to themovable portion 19 composed of the weight portion 13 and the magneticcircuit portion 17, whereby the movable portion 19 vibrates.

[0019] In particular, in the case where the frequency of an electricsignal applied to the voice coil 18 is identical with a resonancefrequency (about 50 to 200 Hz) of the mechanical vibration system, themovable portion 19 largely vibrates. Vibration of the movable portion 19is transmitted from the suspensions 14 to the frame 9, thereby vibratingthe frame 9.

[0020] However, when the movable portion 19 performs rolling movementsduring vibration, the outer periphery of the movable portion 19 may comeinto contact with the inner diameter of the frame 9 to generate anabnormal sound. Therefore, in order to prevent this, the suspensions 14support the center of gravity of the movable portion 19 at a verticallysymmetric position (equal distance).

[0021] The size of the vibration of the mechanical vibration system isproportional to the product of the mass and an acceleration of themovable portion 19. Thus, when the weight portion 13 is provided in themagnetic circuit portion 17, the mass of the mechanical vibration systemis increased, and vibration with a large amplitude can be obtained. Whenthe frame 9 is fixed, for example, in a housing of a portable terminalapparatus, a function of calling or the like can be performed byvibrating the housing. The weight portion 13 is provided mainly at theouter periphery of the magnetic circuit portion 17 which is positionedoutside of the minimum cross-sectional area through which a magneticflux of the magnetic circuit portion 17 passes. Mainly, as describedabove, in order to increase the mass of the mechanical vibration system,the weight portion 13 is integrated with the magnetic circuit portion 17or attached thereto as a separate component.

[0022] On the other hand, the diaphragm 8 vibrates with an electricsignal (having an audible frequency of about 500 Hz or more) applied tothe voice coil 18, thereby generating a sound.

[0023] Thus, according to the structure of theelectric-mechanical-acoustic converter in the present example, vibrationperformance can be stabilized, and damage to the converter anddegradation of performance thereof caused by shock such as a drop can beprevented.

EXAMPLE 2

[0024]FIG. 2 is a perspective view of an assembly of a movable portionand suspensions which are main portions of another example of anelectric-mechanical-acoustic converter of the present invention. In FIG.2, the identical portions (with those in Example 1) are denoted by thereference numerals identical with those therein. The description thereofis omitted, and only the differences will be described.

[0025] Referring to FIG. 2, when one end of each suspension 14 is moldedwith resin, a rib 21 for welding to the mold portion 16 issimultaneously formed. When the mold portion 16 is welded to the frame9, each suspension 14 can be connected to the frame 9 within a shortperiod of time. Even in the case where there are a plurality ofsuspensions 14, the suspensions 14 can be connected to the frame 9 withgood precision, simultaneously using an integrated welding jig.

[0026] A pair of the suspensions 14 are attached to upper and lowersurfaces of the yoke 10 in such a manner that a distance and stiffnessare symmetrically distributed in an inverse ratio with respect to thecenter of gravity of the movable portion 19 in a vertical direction.This prevents the movable portion 19 from performing rolling movements,and prevents an abnormal sound from being generated by the contactbetween the side surface of the movable portion 19 and the frame 9.

EXAMPLE 3

[0027]FIG. 3 is a perspective view of an assembly of a movable portionand suspensions which are main portions of another example of anelectric-mechanical-acoustic converter of the present invention. In FIG.3, the identical portions (with those in Example 1) are denoted by thereference numerals identical with those therein. The description thereofis omitted, and only the differences will be described.

[0028] Referring to FIG. 3, a connected portion between the suspensions14 and the frame 9 is molded with resin, a plurality of fulcrums of thesuspensions 14 are integrally molded while the suspensions 14 arepreviously connected to the movable portion 19, whereby the moldportions 16 are formed. Since a plurality of fulcrums of the suspensions14 are simultaneously connected with good precision, vibrationperformance is stabilized.

[0029] A frame bottom plate 9 b which integrates each mold portion 16corresponds to the bottom surface of the frame 9 (in Example 1). Theframe bottom plate 9 b does not have a wall surface, so that the cover 9a is extended downward, or a frame structure is attached.

EXAMPLE 4

[0030]FIG. 4 is a perspective view of another example of anelectric-mechanical-acoustic converter of the present invention. In FIG.4, the identical portions (with those in Example 1) are denoted by thereference numerals identical with those therein. The description thereofis omitted, and only differences will be described.

[0031] Referring to FIG. 4, a pair of suspensions 14 are provided onupper and lower surfaces of the yoke 10. One end of each suspension 14is fixed to the dead-end portion 13, and the other end thereof is weldedto a metal chip 22 which is insert-molded in the frame 9.

[0032] Because of the above, the suspensions 14 can be connected to theframe 9 within a short period of time, and high connection strength canbe obtained. Furthermore, the metal chip 22 and a lead terminal 23 areintegrally formed on a lead frame 24, and integrally molded to the frame9. Due to this, it becomes possible to integrate components and simplifyassembly steps.

[0033] In the present example, the metal chip 22 and the lead terminal23 are integrally formed on the lead frame 24. However, one of thesuspensions 14 can be integrally formed on the lead frame 24.Furthermore, even in the case of using no metal chip 22, the leadterminal 23 and one of the suspensions 14 can be integrally formed onthe lead frame 24. This contributes to the reduction in the number ofcomponents and automation of assembly steps.

EXAMPLE 5

[0034]FIG. 5 is a partial cross-sectional side view showing a statewhere an example of an electric-mechanical-acoustic converter of thepresent invention is provided in a mobile telephone. Only differences(from Example 1) will be described. Reference numeral 26 denotes abushing made of a rubber-like elastic substance attached so as to coverthe frame 9. Reference numeral 27 denotes an upper case of the mobilephone which is a portable terminal. Reference numeral 28 denotes a lowercase of the mobile phone. Reference numeral 30 denotes a circuitsubstrate fixed to the upper case, on which a liquid crystal displayportion 31 and electronic components are provided.

[0035] Reference numeral 29 denotes a holder fixed to the circuitsubstrate 30, for accommodating the electric-mechanical-acousticconverter covered with the bushing 26. As is understood from FIG. 5, theelectric-mechanical-acoustic converter is attached to the holder 29 insuch a manner that the diaphragm 8 is placed on the circuit substrate 30side.

[0036] When the upper case 27 and the lower case 28 are combined to befixed to each other, the electric-mechanical-acoustic converter ispressure-welded to the mobile telephone via the circuit substrate 30 andthe holder 29 (in this case, the electric-mechanical-acoustic converteris designed to be pressure-welded so that an error of each of the abovecomponents is absorbed by the bushing 26 which is an elastic substance,and vibration of the electric-mechanical-acoustic converter istransmitted to the body of the mobile telephone without fail).

[0037] The bushing 26 is provided with an opening 26 a in a portioncorresponding to a sound generating portion 28 a of the lower case 28.When the diaphragm 8 vibrates to generate a sound, the space between theframe 9 and the movable portion 19 and the opening 26 a are allowed toconduct a sound, whereby a sound is generated from the sound generatingportion 28 a of the lower case 28.

[0038] As described above, the electric-mechanical-acoustic converter isattached to the portable terminal so that the diaphragm 8 is placed onthe circuit substrate 30 side. Therefore, the voice coil 18 is protectedfrom influence from an outer magnetic field, and a sound generated bythe diaphragm 8 can be stably obtained. Furthermore, outer impact isattempted to be absorbed by the bushing 26, and theelectric-mechanical-acoustic converter can be pressure-welded to thebody of the portable terminal. Therefore, vibration for calling can alsobe transmitted to the body of the mobile telephone with good efficiency.

[0039] The opening 26 a may be made of a plurality of small pores or mayhave a large pore as in the present example.

[0040] Furthermore, the bushing 26 will have the above-mentioned effect,even when used in the electric-mechanical-acoustic converter shown inthe prior art.

[0041] Industrial Applicability

[0042] As described above, the electric-mechanical-acoustic converter ofthe present invention includes: a diaphragm; a magnetic circuit disposedso as to oppose the diaphragm; a voice coil one end of which is attachedto the diaphragm, inserted into a magnetic gap of the magnetic circuitwith a predetermined space; a weight integrated with the magneticcircuit or attached thereto as a separate component; at least onesuspension supporting a movable portion composed of the magnetic circuitand the weight; and a frame supporting the diaphragm and the suspension,a space in an elastic deformation range of the suspension being providedbetween the outer periphery of the movable portion and the frame. Evenin the case where a portable terminal apparatus is dropped, and theelectric-mechanical-acoustic converter built therein is subjected toshock, the outer periphery of the movable portion is received by theframe, whereby the suspension can be prevented from being permanentlydeformed. Furthermore, an outstanding electric-mechanical-acousticconverter for practical use can be provided, which resists degradationof a vibration level caused by damage of the movable portion, variationin a vibration frequency, and a decrease in sharpness of resonance dueto damage of a connected portion of the suspension.

[0043] Furthermore, (1) in the case where a space between the outerperiphery of the movable portion and the inner diameter of the frame isset to be smaller than a space between the magnetic gap and the voicecoil, even when the electric-mechanical-acoustic converter is subjectedto shock, the outer periphery of the movable portion is received by theframe before the magnetic gap comes into contact with the voice coil, sothat the voice coil can be prevented from being damaged.

[0044] (2) In the case where the suspension supports the movable portionat a position vertically symmetric with respect to the center of gravityof the movable portion, the suspension supports the center of gravity ofthe movable portion at a vertically symmetric position, therebypreventing the movable portion from undergoing rolling movements. Thus,an abnormal sound can be prevented from being generated by the contactbetween the frame and the movable portion due to rolling.

[0045] (3) In the case where the suspensions support the movable portionin such a manner that a distance and stiffness are verticallydistributed in an inverse ratio with respect to the center of gravity ofthe movable portion, even when the position of the center of gravity isnot placed at an equal distance from the suspensions in a verticaldirection, the movable portion can be prevented from undergoing rollingmovements. Thus, an abnormal sound can be prevented from being generatedby the contact between the frame and the movable portion due to rollingof the movable portion.

[0046] Furthermore, the electric-mechanical-acoustic converter of thepresent invention includes: a diaphragm; a magnetic circuit disposed soas to oppose the diaphragm; a voice coil one end of which is attached tothe diaphragm, inserted into a magnetic gap of the magnetic circuit witha predetermined space; a weight integrated with the magnetic circuit orattached thereto as a separate component; at least one suspensionsupporting a movable portion composed of the magnetic circuit and theweight; and a frame supporting the diaphragm and the suspension, whereinone end of the suspension is molded with resin, and the mold portion isattached to the frame. In this converter, a portion of the suspensionattached to the frame is specified, so that a fulcrum of the suspensionis determined. Thus, an electric-mechanical-acoustic converter can beprovided, in which performance during production is stable. In the casewhere the mold portion obtained by molding one end of the suspensionwith resin in the above-mentioned structure is inserted to be fixed in aconcave portion provided in the frame, all the portions can besimultaneously assembled with good precision and strength. Furthermore,since a fulcrum of the suspension is molded, vibration characteristicscan be prevented from being changed by shock.

[0047] Furthermore, the electric-mechanical-acoustic converter of thepresent invention includes: a diaphragm; a magnetic circuit disposed soas to oppose the diaphragm; a voice coil one end of which is attached tothe diaphragm, inserted into a magnetic gap of the magnetic circuit witha predetermined space; a weight integrated with the magnetic circuit orattached thereto as a separate component; at least one suspensionsupporting a movable portion composed of the magnetic circuit and theweight; and a frame supporting the diaphragm and the suspension, whereina connected portion of the suspension on the frame side is insert-moldedto the frame.

[0048] In this converter, the connected portion of the suspension withrespect to the frame is integrally molded with resin under the conditionthat the suspension is connected to the movable portion. Thus, anoutstanding electric-mechanical-acoustic converter can be provided, inwhich assembly can be performed with good precision of a fulcrum of thesuspension and positional relationship.

[0049] Furthermore, (1) in the case where the connected portion of thesuspension on the frame side is welded to a metal chip one end of whichis insert-molded to the frame in the above-mentioned structure, assemblycan be performed with good precision of a fulcrum of the suspension andpositional relationship, and strength can be obtained by welding.

[0050] Furthermore, (2) in the case where a metal chip and a leadterminal which receives an electric signal from outside are formed on anidentical lead frame, an electric-mechanical-acoustic converter can beproduced without increasing the number of components, and assembly stepscan be simplified.

[0051] Furthermore, the electric-mechanical-acoustic converter of thepresent invention includes: a diaphragm; a movable portion composed of amagnetic circuit disposed so as to oppose the diaphragm; a voice coilone end of which is attached to the diaphragm, inserted into a magneticgap of the magnetic circuit; a suspension supporting the movableportion; a frame supporting the diaphragm and the suspension; and anelastic bushing covering the frame, provided with an opening at least onan outside of the movable portion for conducting a sound to a portableterminal, and interposed in the portable terminal. In this converter,the frame is covered with the elastic bushing and the bushing isinterposed in the portable terminal. Therefore, in the case where theportable terminal (e.g., a mobile telephone) is dropped, shock caused bythe drop is absorbed, and the opening of the bushing conducts a sound toa sound generating portion of the portable terminal, whereby asatisfactory sound can be obtained.

[0052] Furthermore, according to the method for producing anelectric-mechanical-acoustic converter including: a diaphragm; amagnetic circuit disposed so as to oppose the diaphragm; a voice coilone end of which is attached to the diaphragm, inserted into a magneticgap of the magnetic circuit with a predetermined space; a weightintegrated with the magnetic circuit or attached thereto as a separatecomponent; at least one suspension supporting a movable portion composedof the magnetic circuit and the weight; and a frame which is a housingsupporting the diaphragm and the suspension, the suspension and a leadterminal through which an electric signal is applied from outside to thevoice coil are formed on a lead frame and integrally molded therewith.Thus, the suspension and the lead terminal are formed on the lead frame,whereby the number of components is reduced, and assembly may beautomated.

[0053] List of Reference Numerals in the Drawings

[0054]1 . . . vibration plate

[0055]2 . . . case

[0056]3 . . . yoke

[0057]4 . . . magnet

[0058]5 . . . bottom plate

[0059]6 . . . suspension

[0060]7 . . . voice coil

[0061]8 . . . vibration plate

[0062]9 . . . frame

[0063]9 a . . . cover

[0064]9 b . . . frame bottom plate

[0065]10 . . . yoke

[0066]11 . . . magnet

[0067]12 . . . plate

[0068]13 . . . dead-weight

[0069]14 . . . suspension

[0070]15 . . . concave portion

[0071]16 . . . mold portion

[0072]17 . . . magnetic circuit portion

[0073]18 . . . voice coil

[0074]19 . . . movable portion

[0075]20 . . . space

[0076]21 . . . rib

[0077]22 . . . metal chip

[0078]23 . . . lead terminal

[0079]24 . . . lead frame

[0080]26 . . . bushing

[0081]26 a . . . opening

[0082]27 . . . upper case

[0083]28 . . . lower case

[0084]28 a . . . sound generating portion

[0085]29 . . . holder

[0086]30 . . . circuit substrate

[0087]31 . . . liquid crystal display portion

1. An electric-mechanical-acoustic converter, comprising: a diaphragm; amagnetic circuit disposed so as to oppose the diaphragm; a voice coilone end of which is attached to the diaphragm, inserted into a magneticgap of the magnetic circuit with a predetermined space; a weightintegrated with the magnetic circuit or attached thereto as a separatecomponent; at least one suspension supporting a movable portion composedof the magnetic circuit and the weight; and a frame supporting thediaphragm and the suspension, a space in an elastic deformation range ofthe suspension being provided between an outer periphery of the movableportion and the frame.
 2. An electric-mechanical acoustic converteraccording to claim 1, wherein a space between the outer periphery of themovable portion and an inner diameter of the frame is set to be smallerthan a space between the magnetic gap and the voice coil.
 3. Anelectric-mechanical acoustic converter according to claim 1, wherein thesuspension supports the movable portion at a position verticallysymmetric with respect to a center of gravity of the movable portion. 4.An electric-mechanical-acoustic converter according to claim 1, whereinthe suspension supports the movable portion in such a manner that adistance and stiffness are symmetrically distributed in an inverse ratiowith respect to a center of gravity of the movable portion in a verticaldirection.
 5. An electric-mechanical-acoustic converter, comprising: adiaphragm; a magnetic circuit disposed so as to oppose the diaphragm; avoice coil one end of which is attached to the diaphragm, inserted intoa magnetic gap of the magnetic circuit with a predetermined space; aweight integrated with the magnetic circuit or attached thereto as aseparate component; at least one suspension supporting a movable portioncomposed of the magnetic circuit and the weight; and a frame supportingthe diaphragm and the suspension, wherein one end of the suspension ismolded with resin, and the mold portion is attached to the frame.
 6. Anelectric-mechanical-acoustic converter according to claim 5, wherein oneend of the suspension is molded with resin, and the mold portion isinserted to be fixed in a concave portion provided in the frame.
 7. Anelectric-mechanical-acoustic converter, comprising: a diaphragm; amagnetic circuit disposed so as to oppose the diaphragm; a voice coilone end of which is attached to the diaphragm, inserted into a magneticgap of the magnetic circuit with a predetermined space; a weightintegrated with the magnetic circuit or attached thereto as a separatecomponent; at least one suspension supporting a movable portion composedof the magnetic circuit and the weight; and a frame supporting thediaphragm and the suspension, wherein a connected portion of thesuspension on the frame side is insert-molded to the frame.
 8. Anelectric-mechanical-acoustic converter according to claim 7, wherein theconnected portion of the suspension on the frame side is welded to ametal chip one end of which is insert-molded to the frame.
 9. Anelectric-mechanical-acoustic converter according to claim 8, wherein themetal chip and a lead terminal which receives an electric signal fromoutside are formed on an identical lead frame and are integrally moldedtherewith.
 10. An electric-mechanical-acoustic converter, comprising: adiaphragm; a movable portion composed of a magnetic circuit disposed soas to oppose the diaphragm; a voice coil one end of which is attached tothe diaphragm, inserted into a magnetic gap of the magnetic circuit; asuspension supporting the movable portion; a frame supporting thediaphragm and the suspension; and an elastic bushing covering the frame,provided with an opening at least on an outside of the movable portionfor conducting a sound to a portable terminal, and interposed in theportable terminal.
 11. A method for producing anelectric-mechanical-acoustic converter including: a diaphragm; amagnetic circuit disposed so as to oppose the diaphragm; a voice coilone end of which is attached to the diaphragm, inserted into a magneticgap of the magnetic circuit with a predetermined space; a weightintegrated with the magnetic circuit or attached thereto as a separatecomponent; at least one suspension supporting a movable portion composedof the magnetic circuit and the weight; and a frame which is a housingsupporting the diaphragm and the suspension, wherein the suspension anda lead terminal through which an electric signal is applied from outsideto the voice coil are formed on a lead frame and integrally moldedtherewith.